With the recent increase in concern about environmental issues, the demand on automobiles for better fuel economy has been increasing. Higher fuel economy is also required of rubber compositions for automotive tires. For example, rubber compositions containing conjugated diene polymers such as polybutadiene or a butadiene-styrene copolymer and filler such as carbon black or silica are used in automotive tires.
Patent Literature 1, for example, proposes a method for improving fuel economy by using a diene rubber (modified rubber) that has been modified with an organosilicon compound containing an amino group and an alkoxy group. Although fuel economy is improved by such conventional techniques, another important challenge from economic and safety standpoints is to ensure sufficient abrasion resistance and sufficient tensile properties (rubber tensile strength). Regarding this issue, the conventional techniques unfortunately do not sufficiently provide abrasion resistance, which is in a trade-off relationship with fuel economy, and can also cause rubber chipping. It is still difficult to improve fuel economy while simultaneously improving rubber tensile strength and abrasion resistance.